Fisika Study Center

A homogeneous solid cylinder named A, with mass m₁ is freely to rotate in it's axis. The cylinder is connected to block B with mass m₂ See the figure.



Constant force F applied to the end of the string that is wrapped around the cylinder. Ignore all possible frictional forces, find:
(a) the acceleration of the rope end
(b) kinetic energi after t sec
Source of problem: Mekanika 1-Prof Yohanes Surya

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Physics.fisikastudycenter.com, Physics Olympiads problem series, olympiads preparation for beginner level, high school level. The needed basic concepts for this problems are forces (weight, frictional force, string tension), Newton's Laws.

Problem 13
Given three masses: m_A = 40 kg, m_B, dan m_C = 50 kg. The static frictional force coefficient between A and B is 0.3, between A the table is 0,2. See the figure!



Calculate the minimum mass of B so the system remains rest!
Question source: Fisika Study Center-Modification of UMPTN 1994 / Indonesian colleges examination entrance

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Physics.fisikastudycenter.com, olympiad problems series, high school olympiads preparation, for beginner level, forces and newton's laws.

Problem 12
A mechanical system consisting of four masses m₁, m₂, m₃ and m₄. See the figure.



A horizontal force F is now applied to cart m₄ as shown. The size of F is such that m₁, m₂ and m₃ remain at rest relative to m₄. Ignore the mass and frictional forces of string and pulley, find the magnitude of F and the system acceleration ! Use g = 10 m/s² and the four masses respectively are 0,3 kg, 0,4 kg, 0,5 kg and 2,8 kg!
Problem source: Fisika Study Center-Modification of ³rd International Physics Olympiad 1969, Brno, Czechoslovakia, Problem 1

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Physics.fisikastudycenter.com,- Olympiads problem serie, Physics olympiads preparation for beginners, high school students level,Problem # 11, the needed basic concepts in this problem are forces (weight, string tension, rope tension) and Newton's laws.

Problem 11
Two block, m₁ dan m₂ of 6 kg and 4 kg respectively in a pulleys systems. See the figure.



Use the acceleration due to gravity g = 10 m/s², find the accelerations of m₁ and m₂ , ignore the mass of pulleys and assume there is no frictional force acting between the string/rope and the pulleys!

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